je.st
news
Subtropical Storm Leslie Forecast Discussion Number 5
2018-09-24 16:34:42| National Hurricane Center (Atlantic)
Issued at 1100 AM AST Mon Sep 24 2018 138 WTNT43 KNHC 241434 TCDAT3 Subtropical Storm Leslie Discussion Number 5 NWS National Hurricane Center Miami FL AL132018 1100 AM AST Mon Sep 24 2018 Conventional satellite imagery shows little change in Leslie's cloud pattern during the past several hours with the exception of a few new isolated thunderstorms developing near the surface center. Accordingly, the initial intensity for this advisory is kept at 35 kt. The statistical intensity guidance and the large-scale models show Leslie commencing a strengthening trend in 24 hours as a mid-latitude baroclinic system digs southeastward toward the cyclone. Some of the models also indicate that Leslie, after completing an extratropical transition in around 48 hours, will deepen and generate a large area of gale force winds, particularly in the northwest quadrant. The NHC intensity forecast reflects this scenario and is just below the IVCN intensity consensus. The initial motion is estimated to be an eastward drift, or 090/4 kt within the increasing mid-level westerly steering flow. A turn to the east-northeast is forecast as an approaching mid-latitude trough and associated cold front approaches from the northwest over the central Atlantic. The deterministic guidance indicate that the aforementioned baroclinic system will overtake Leslie near the 48 hour period, and influence a transition to a non-tropical low pressure system. Subsequently, the GFS and the European models still show extratropical Leslie as the primary system and deepening with time. For now, the official forecast will indicate a merging scenario, but succeeding advisories may include extratropical low forecast points through day 5. FORECAST POSITIONS AND MAX WINDS INIT 24/1500Z 32.5N 48.0W 35 KT 40 MPH 12H 25/0000Z 32.5N 47.2W 35 KT 40 MPH 24H 25/1200Z 32.4N 45.5W 40 KT 45 MPH 36H 26/0000Z 32.3N 42.8W 45 KT 50 MPH 48H 26/1200Z 33.6N 39.9W 50 KT 60 MPH...POST-TROP/EXTRATROP 72H 27/1200Z...MERGED WITH FRONT AND LARGER LOW $$ Forecaster Roberts
Tags: number
discussion
storm
forecast
Category:Transportation and Logistics